Aspirator



G. G. BUDWIG May 8, 1956 ASPIRATOR 2 Sheets-Sheet l Filed June 29, 1953 m 5527' q. suow/q q INVENTOR. 22

y 8, 1956 r G. G. BUDWIG 2,744,791

ASPIRATOR Filed June 29, 1953 2 Sheets-Sheet 2 q/z. 5527' q. sway/q INVENTOR.

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prro/e/vev United States Patent ASPIRATOR Gilbert G. Budwig, North Hollywood, Calif.

Application June 29, 1953, Serial No. 364,835

10 Claims. (Cl. 299-142) This invention relates to devices for mixing and distributing liquids, and more particularly to liquid mixing and spraying devices of the type that operate. upon the principle of aspiration. The present invention constitutes an improvement over those forming the respective subjects matter of Patent No. 2,030,853, issued to me on February 18, 1936, and Patent No. 2,061,932, issued to me on November 24, 1936, and my co-pending application Serial No. 347,961, filedApril 10, 1953.

An object of the present invention is to provide an improved apparatus'for mixing diluent liquid with concentrated liquid and applying the resultant mixture to external objects.

Another object is to provide a device for diluting concentrated liquids which operates upon the principle of aspirating the concentrate by vacuum developed under a sheet of the diluent liquid passing over the upper end of an aspiration orifice, and in which means are provided for compensating for high viscosity of the concentrated liquid and for the presence of solid or semi-solid particles therein which might otherwise tend to clog the aspiration orifice. p

The invention possesses other objects and advantageous features, some of which, with those enumerated, will be set forth in the following description of the apparatus illustrated in the drawings accompanying and forming part of this specification. It is to be understood that I am not to be limited to the showing made by the said drawings and description but that variations may be made of the forms of the apparatus illustrated and described therein without departing from the spirit and scope of the invention as defined by the claims.

Referring to the drawings:

Figure 1 is a side elevation of a liquid mixing and spraying device embodying the principles of the present invention. Part of the figure is broken away to reduce its size.

' Figure 2 is a front elevation of the mixing and spraying device of Fig. 1.

Figure 3 is an enlarged vertical, medial sectional view taken on the line 3-3 of Fig. 2 with the direction of view as indicated.

Figure 4 is a top plan view.

Figure 5 is a detail plan view, drawn to enlarged scale, of a portion of the distributing surface and the aspirating orifice and vacuum increasing recess therein, of the apparatus of Figs. 1 to 4, inclusive.

Figure 6 is a vertical sectional 6-6 of Fig. 5.

Figures 7, 9, and 11 are views similar to Fig. 5, each showing a modified form of vacuum increasing recess.

Figures 8, 10, and 12 are vertical sectional views taken, respectively, on the lines 8-8, 1010, and 12-12 of Figures 7, 9, and 11.

Figures 13 and 14 are vertical sectional views similar to Figures 6, 8, 10, and 12, and each showing further modification of vacuum increasing recesses.

The improvements contemplated by the present invention are incorporated into a spray gun similar to each view taken on the line of those disclosed in my prior patents and pending application aforesaid, comprising a nozzle adapted to be attached to a source of fluid under pressure, such as a garden hose, and adapted to direct its jet obliquely onto a distributing surface so that the jetspreads out into a fan shaped sheet passing over an aspiration orifice in the surface. The orifice communicates with a supply of concentrated liquid which is aspirated through the orifice into the fan shaped sheet where it mixes with and is diluted by the jetted liquid to the degreeof concentration at which it is advantageous to apply the mixture to external objects. After mixing, the dilute liquid is projected from the distributing surface in the form of a spray traveling at considerable velocity and for a considerable distance, with the result that the apparatus provides a convenient device, particularly for home gardeners, for diluting concentrated liquid insecticides and fungicides and applying them to plants, for diluting concentrated liquid weed killing chemicals and spraying it on the ground, lawn areas and the like, and diluting concentrated liquid fertilizer and applying it to the ground.

Referring first to that modification of my invention which is illustrated in Figures 1 to 4, inclusive, there is provided a body portion, indicated generally at 11, and preferably in the form of a die casting. An extension 12 formed integrally with the body portion 11 at one side thereof, is of tubular form, having an internally threaded socket 13 to which the male threads of a conventional garden hose coupling can be secured. The extension 12 also is provided with a jet hole, or nozzle 14, the bore of which communicates with the socket 13. This nozzle 14 is adapted to direct its jet, preferably in round, pencillike form onto a substantially flat distributing surface 16 at an oblique angle thereto so that after the jet 15 has impinged upon the distributing surface 16 it spreads out into a water fan or sheet, as indicated at 17 in Figure 4.

The distributing surface 16 is provided upon the upper surface of a platform 21 which projects upwards a suitable distance above the main portion 22 of the body 11; and the main portion 22 is provided in its under surface with a circular socket 28, the circumferential wall of which is interiorly threaded so that the threaded neck 29 of a bottle 30, preferably of conventional and commonly occurring form, can be attached to the under surface of the body 11, as shown in Figure 3. The bottle 30 serves as a reservoir for the concentrated liquid which the device is intended to dilute and spray.

The parts are so proportioned and arranged that the pencil-like jet 15 from the nozzle 14 impinges upon the distribution surface 16 just before it reaches an aspiration or suction aperture 31, the upper end of which opens through the distribution surface 16 and which extends downwards therefrom through a tubular projection 32 which preferably is coaxially arranged within the socket 28. A preferably flexible tube. 33, secured at its upper end by being slipped over this projection 32 thus estab lishes communication between the suction aperture 31 and the reservoir attached to the under surface of the body 11. This suction tube 33 preferably extends to a position closely adjacent the bottom of the reservoir bottle so that substantially the entire contents of the reservoir can be aspirated before the supply of concentrated liquid needs replenishing. impingement of the jet 15 against the surface 16 just before it reaches the upper end of the suction aperture 31, causes the fan-shaped sheet 17 to pass, at considerable velocity, over the upper end of the suction aperture 31. This causes a vacuum to be developed within the suction aperture 31 so that fluid within the bore of the projection 32 and Within that of the tube 33, will be drawn upwards through the suction aperture 31 to mix with andconsequently to be diluted by the liquid jetted onto the surface 16 from the nozzle 14.

One of the problems presented in the design of aspirating apparatus of the character described arises from the fact that many of the insecticides, fungicides, fertilizers and other agricultural chemicals to be sprayed, which are commercially available in concentrated liquid form, and accordingly suited for use in an aspirating sprayer, are characterized by high viscosity and the presence therein of particles, of solid or semi-solid matter. These properties of a concentrate are apt to interfere with uninterruptedly even flow of concentrate through the aspiration orifice to the sheet of diluting water and therefore prevent the uniformity of concentration of the ultimate sprayed mixture which is necessary for optimum, dependable operation of the sprayer. What would appear to be the obvious manner of compensating for both high viscosity of the concentrate and the presence of solid and semi-solid particles therein is to increase the size of the aspiration orifice. But this also increases the fiow capacity of the orifice, with the result that too much of the liquid concentrate is aspirated to be consistent with the safe and economical use of the material.

My experimental exploration of the problem has revealed that a better and more dependable way of promoting uniformity of flow of a highly viscous and lumpy concentrate through the aspiration orifice is by increasing the pressure differentiate between the top and the bottom of the column of liquid concentrate rising to the orifice, and thereby increasing the physical force causing the flow of concentrate, rather than by resorting to a less restricted orifice. I have also found that the presence of a recess in the distributing surface of the apparatus, where the concentrate first encounters the diluent liquid, effectually increases the vacuum developed by the fan-shaped sheet of diluent over the orifice, and that the size and shape of the recess, and its location with respect to the orifice, all have a significant effect upon the extent of increase in the vacuum attained. Whereas I am unable to account for the different effects produced in the increase in vacuum which are attained by recesses of different shape, size and location, results attained experimentally indicate that the shape and character of the various angular edges where the defining walls of the recess intersect the distributing surface, and where the wall of the orifice intersects the recess constitute one of the determining factors.

Within certain limits, increase in size (plan) of the recess and increase .in recess depth are accompanied by increase in vacuum and a substantially proportionate increase in flow of concentrate through the aspiration orifice. An acute included angle of intersection of the recess and distribution surface at the side of the recess over which the sheet of liquid last passes has been found to be of importance in maintaining a high aspirating vacuum; and another of the important details of the present invention is involved with the nature of the angle of intersection of the bottom of the recess and the wall. of the aspiration orifice remote from the nozzle by which the diluent liquid is jetted. The especial importance attaching to this last mentioned angle is that if this angle is sharp and acute, it has a surprising influence toward increasing the aspiration vacuum, but with an increase in rate of flow of the concentrate which is less than proportional to the increase in vacuum.

Accordingly, by arriving at a proper balance between size, shape, and arrangement of the vacuum, increasing recess, and angularity of intersection of the bottom of the recess with the wall of the orifice, a suitable rate of flow of concentrate can be attained and in such a manner that the tending for high viscosity of, and lumps in, the concentrate to impede flow of concentrate is minimized.

A vacuum-increasing recess 41 of the general configuration, size with relation to the aspiration orifice 31, and positional relationship to the orifice, such as illustrated in Figures 3 to 6, inclusive, has been found to be highly advantageous in achieving a rate of flow of concentrate which will produce a suitable spraying mixture. As brought out in the hereinabove discussion of the characteristics desirable in the vacuum increasing recess, the angle 42 between the bottom Wall 43 of the recess 41 and the wall 44 of the aspiration orifice 31 farthest from the nozzle 14 is acute, preferably approximately 45. Moreover, the two surfaces 43 and 44 meet in a sharp line 46, such as that normally produced by machining the two surfaces without charnfering or rounding their meeting edge. in order to develop the desired acute characteristic of this angle 42, the recess 41 is formed with its bottom Wall sloping downward and forward (i. e., downward and in the direction in which the fan-shaped sheet 1'? passes over the recess 41) from the orifice 31. This is easily accomplished by forming the recess 41 (or the hob used in the manufacture of a die for the quantity production thereof) with a round pointed drill, and drilling therewith about a center slightly forward of the forward boundary of the orifice 44 (or the counterpart of the orifice 44 in the hob), thus placing the deepest portion 47 of the recess forward of the front edge of the recess, as best shown in Fig. 6. The diameter of the recess 41 at its top, or widest portion, is between two and two and a half times the diameter of the orifice 31, and accordingly the diameter of the round pointed drill used should be such that a recess 31 of this size will be formed when p the angle between the surface 16 and the bounding wall of the recess 31 is approximately this being accomplished most readily by sinking the drill only until its round point reaches a depth slightly less than the diameter of the drill. Using a round pointed drill of the appropriate diameter and in this manner forms the angle 48 included between the plane of the surface 16 and the bounding wall 49 of the recess, at something less than a right angle. Experimentation has demonstrated that if this angle 47 is approximately 80", it has much influence upon increasing the vacuum developed in the aspiration orifice 31.

Figures 7 and 8 illustrate a modified form of recess 41A which has been found to increase the vacuum Within the orifice 31A more effectually than the recess 41 first described, as the increase in vacuum attained by the recess appears to be approximately proportional to the area of the top of the recess. The recess 41A is formed in much the same manner as the recess 41, the round pointed drill being kept perpendicular to the distribution surface 16A and operated about a center axis slightly forward of the aspiration orifice 31A, thus locating the deepest portion 47A of the recess 41A far enough forward of the orifice 31A to develop the acute angle 42A of inter section of the bottom 43A of the recess and the forward wall 44A of the orifice. When the drill has been sunk far enough to develop the angle 47A included between the forward wall 49A of the recess and the surface 16A to approximately 80, the drill is moved laterally in a straight line to both sides of the orifice 16A, thus developing a recess 41A elongated transversely with respect to the fan-shaped sheet 17 passing over the orifice and recess. As a result, the top of the recess 41A is bounded by semi-circular ends 51 and straight line front and back edges 52 and 53, respectively, the latter of which substantially bisects the top of the aspiration orifice 31A.

In other respects, however, the recesses 41 and 41A are similar, since the cross section of each of the recesses, taken in the direction in which water of the fan-shaped sheet passes over, has the configuration of a segment of a circle less than a semi-circle.

The, form of recess 41B illustrated in Figures 9 and i0 is made 'in the same way as that of Figures 7 and 8, except that the round pointed drill is slanted forward (upper end of drill farther in the direction of water movement) at approximately 45. The result is that the front bounding wall 493 takes its form from the straight side of the drill rather than from the round bottom of the drill, and consequently the angle 47B of intersection of the front wall 49B of the recess 41B and the distributing surface 16B is approximately 45 This nature of angle 473 has been found to be advantageous in that it develops slightly less flow of aspirated concentrate, but with no appreciable diminution of the vacuum developed in the aspiration orifice 31B. Moreover, the magnitude of the angle 4213 between the bottom 43B of the recess 41B and the front wall 44B of the orifice 31B is the same as that of the angles 42 and 42A, since it takes its form from the round bottom of the drill.

In Figures 11 and 12 a still further modified form of recess 41C is shown. This is formed in the same manner as that of Figures 9 and 10, with the round pointed drill slanted forward, but moving in an arcuate line to each side of the aspiration orifice 31C, to define the recess 41C by arcuate lines 56 and 57 instead of the straight line front and back edges as in the case of recesses 41A and 41B. The curvature of the arcuate edges 56 and 57 is such that their convex sides face aft, i. e., toward the diluent jetting nozzle 14. I

The modification shown in Figures 11 and 12, however, is similar to that of Figures 9 and 10, in that a cross section taken in a vertical plane including the axis of the aspiration orifice and parallel to the direction of water flow, is such that the boundary wall proximal to the water nozzle describes a circular arc with the bottom 47B, 47C beyond and lower than the upper edge of the front wall 44B, 44C of the aspiration orifice. Also, in each recess 41B, 41C, the front bounding wall 49B, 490 describes a straight line intersecting the plane of the distribution surface 16B, 16C in an angle of approximately 45.

A further advantage deriving from the transverse elongation of the recesses 41A, 41B and 41C, in addition to the mentioned increase in aspiration vacuum, is that more even distribution of the concentrate throughout the entire width of the fan-shaped sheet 17 and the spray therefrom is attained, thus making far more uniform results in the application of the diluted concentrate. This advantage is common to all three forms of recess 41A, 41B, and 41C, but is most pronounced in the case of form 41C, wherein the forwardly curving arms of the recess seem to assist in carrying concentrate laterally to the outer edges of the fan-shaped sheet 17.

In the modification shown in Figure 13, an upstanding ridge 61 is provided on the distribution surface 16D between the top of the aspiration orifice 31D and the diluent nozzle. The ridge 61 is of triangular cross section, and is located so close to the orifice 31D that the after wall 62 of the orifice intersects the bottom edge of the front sloping wall 63 of the ridge which is considerably steeper than the after wall 64. This ridge 61 deflects the fan-shaped sheet 17 upward at a steeper angle as it passes over the orifice 31D and the recess 41D, thereby increasing the vacuum which the moving sheet 17 develops within the orifice 31D. 7

A similar transverse ridge 66 is shown in Figure 14. In this case, however, the front and back faces 67 and 68, respectively, of the ridge are of similar size.

It has been found that either of the ridges 61 or 66 can be incorporated with any one of the modifications of Figures 1 to 12, inclusive, with similarly beneficial results in increasing the aspiration vacuum.

Having thus described my present invention as embodied in several different modifications, that which I seek toprotect by Letters Patent is described in the following claims:

I claim:

1. A liquid mixing and spraying apparatus, comprising: a body defining a substantially fiat impingement surface having an aspiration orifice intersecting surface and a recess at one side of and intersecting said orifice, said recess being substantially semicircular across an axis passing through said orifice, and deepest immediately beyond said orifice to form an acute angle therewith at said axis; the width-to-depth ratio of said recess being approximately two-to-one, and the width of said recess to the diameter of said orifice being a ratio between two-toone and three-to-one; and a nozzle adapted to direct a spray of liquid obtusely across said impingement surface to impinge adjacent said orifice and spread fan-wise to form a spray sheet covering said orifice and recess.

2. A liquid mixing and spraying apparatus as set forth in claim 1, wherein: said recess is circular in plan.

3. A liquid mixing and spraying apparatus as set forth in claim 1, wherein: said recess extends laterally of said orifice and its lateral length is greater than its width.

4. A liquid mixing and spraying apparatus as set forth in claim 1, wherein: the trailing margin of said recess with respect to the direction of flow of said liquid sheet forms an angle between and 5. A liquid mixing and spraying apparatus as set forth in claim 1, wherein: the trailing margin of said recess with respect to the direction of flow of said liquid sheet forms an angle of approximately 45.

6. A liquid mixing and spraying apparatus, compris ing: a body defining a substantially flat impingement surface having an aspiration orifice intersecting surface and a recess at one side of and intersecting said orifice, said recess being substantially semicircular across an axis passing through said orifice, and deepest immediately beyond said orifice to form an acute angle therewith at said axis; the width-to-depth ratio of said recess being approximately two-to-one, and the width of said recess to the diameter of said orifice being a ratio between two-to-one and three-to-one; said impingement surface having a transverse rib immediately beyond the margin of said recess remote from said orifice; and a nozzle adapted to direct a spray of liquid obtusely across said impingement surface to impinge adjacent said orifice and spread fan-wise to form a spray sheet covering said orifice and recess and deflected upwardly by said transverse rib.

7. A liquid mixing and spraying apparatus as set forth in claim 6, wherein: said recess is circular in plan.

8. A liquid mixing and spraying apparatus as set forth in claim 6, wherein: said recess extends laterally of said orifice and its lateral length is greater than its width.

9. A liquid mixing and spraying apparatus as set forth in claim 6, wherein: the trailing margin of said recess with respect to the direction of flow of said liquid sheet forms an angle between 75 and 90.

10. A liquid mixing and spraying apparatus as set forth in claim 6, wherein: the trailing margin of said recess with respect to the direction of flow of said liquid sheet forms an angle of approximately 45 References Cited in the file of this patent UNITED STATES PATENTS 2,030,853 Budwig Feb. 18, 1936 2,061,932 Budwig Nov. 24, 1936 2,571,871 Hayes Oct. 16, 1951 

